Hollow rotary bit head with end opening gate for sample recovery operations



July 28, 1954 c. L. RAsslEUR 3,142,346

HOLLOW ROTARY BIT HEAD WITH END OPENING GATE FOR SAMPLE RECOVERY OPERATIONS July 28, 1954 c. L. RAsslEuR 3,142,346

HOLLOW ROTARY BIT HEAD WITH END OPENING GATE FOR SAMPLE RECOVERY OPERATIONS FIGA I* f gli 28m/Ma@ July 2s, 1964 Filed Sept. 10, 1962 FIG.5

C. L. RASSIEUR HOLLOW ROTARY BIT HEAD WITH END OPENING GATE FOR SAMPLE RECOVERY OPERATIONS 5 Sheets-Sheet 5 United States Patent O HOLLOW ROTARY BET HEAD WITH END OPENING GATE FOR SAMPLE RECOVERY OPERATIONS Charles L. Rassieur, University City, Mo., assigner to Central Mine Equipment Company, St. Louis, Mo., a corporation of Missouri Filed Sept. 10, 1962, Ser. No. 222,375 4 Claims. (Cl. 175-270) This invention relates to earth boring equipment and more specifically to a hollow earth boring bit with an open end closed by a gate, which, when open, provides accessibility by way of a hollow drill string for the passage of a sample recovery tool through the bit to the bottom of the hole.

The earth boring equipment to which this invention relates is often used to drive a bit to varying depths in the earth. Depths of 200 to 300 feet below the surface are not unusual for purposes such as subsurface exploration. For this purpose, it becomes necessary to take samples at varying depths as the drilling progresses. A prior application of Theodore E. Rassieur, Serial No. 18,570, tiled March 30, 1960, for Earth Boring Equipment for Core Recovery, shows one kind of a system which is adaptable specifically to the purpose of sampling. This invention, however, represents a different approach to the problem than that shown in this prior application for patent.

It is one of the objects of this invention to provide equipment for earth boring through which a coring or sampling tool may be used.

It is still another object of this invention to provide equipment for earth boring which is hollow end to end, but closed to the passage of a coring or sampling tool when in actual boring operation.

It is still another object of this invention to provide equipment for earth boring which is hollow and a bit for use with this equipment, which may be opened, so that a coring or sampling tool may be inserted through the hollow equipment and the bit Without removing the equipment from the hole.

It is still another object of this invention to provide a hollow earth boring bit, which can be opened to form a through passage for a coring or sampling tool.

According to this invention, a hollow bit threaded at its shank end for engagement with similar threads on the end of a hollow drill string, is constructed at its opposite end with a cutting head having a plurality of bits. Some of these bits are grouped centrally of the head and project beyond or ahead of others. These centrally located bits can be termed leading bits or pilot bits. Other bits are located to cut at the outer periphery of the hole, and follow after the pilot bits. These can be termed outer bits or trailing bits for convenience in distinguishing them from the pilot bits. Still other bits may be used and located in a trailing relation to the pilot bits, but in leading relation to the outer bits. These bits will perform the cutting between the pilot bits and the outer bits. For purposes of convenience, these latter bits may be described as inner trailing bits. Thus, a cutting head has been described, which has a plurality, preferably two or three groups, of bits. One or more of these groups are on a hollow xed part of the cutting head secured to the drill stem, and at least one of these groups is the outer or trailing group of bits which cut at the outer hole diameter. Preferably, the xed part of the cutting head, or the drill string to which it is attached, or both, carry auger iiights to remove cuttings to the top of the hole. The outer trailing group of bits cuts a hole large enough to accommodate passage of the auger flights. One or more 3,142,346 Patented July 28, 1964 of these groups of bits are on a movable or hinged part on the cutting head which movable part is connected to the hollow txed part and swings outwardly from the hollow part to open a passage through the hollow head to the bottom of the hole. This passage will accommodate a coring or sampling tool inserted down the drill string, and through the hollow bit to the bottom of the hole. The same hinged part of the bit when closed, after withdrawal of the tool, obstructs this same passage. The bits on the head are so arranged on the hinged part, that during cutting, the pressure on the bits holds the hinged part closed, or separate mechanical means may be constructed in the bit for this same purpose. Within the bit, there is also a means responsive to tool pressure to open the hinged part.

From this description, the operation of the cutting head during the sample recovery operation will be readily understood. If the pressure on the group of bits on the movable, or hinged, part of the cutting head is removed by raising the tool in the hole, then it is possible to open a passage through the cutting head by forcing the sample recovery tool against the movable part to swing it to open position to pass the sample recovery tool to the bottom of the hole. The size of the hole out by the trailing outer bits provides the clearance in the hole for opening, and the bits in each group are located in an axially, or radially, offset relation so that the groups of bits do not interfere. When the sample recovery tool is withdrawn, the movable part is closed to keep out the cuttings.

Other objects and advantages of this invention will appear from the following detailed description, which is in such clear, concise, and exact terms, as will enable any person skilled in the art to make and use the invention when taken with the accompanying drawings, forming a part thereof, and in which:

FlG. l is a front elevational view of a portion of a drill string and a connected bit constructed in accordance with this invention;

FIG. 2 is a bottom plan view of the tool shown in FIG. 1;

FIG. 3 is a sectional view taken on the line 3 3 of FIG. l, looking in the direction of the arrows;

FIG. 4 is a sectional view taken on the line 4-4 of FIG. 1, looking in the direction of the arrows; and,

FIG. 5 is an operational view showing a portion of the drill string and bit in vertical section with a sampling tube inserted therein. The full lines indicate the parts of the tools in closed position. The dotted lines indicate the same parts when in open position to permit passage of the tool.

Returning now to FIG. 1, the tool, according to this invention, is shown connected with a hollow drill string 1 by a threaded connection, including male threads on the shank 3, and female threads within the string section 1. It will be understood that the section 1 is really one end of a plurality of drill string sections, which are similarly connected together, as shown in FIG. 1. The shank 3, in turn, is connected by being formed as an integral part with the head of the bit generally designated as 5. Both, the shank 3 and the head 5, are hollow as shown at 40 (FIG. 4) providing a through passage to the bottom of the drill head 5. This passage is normally closed during operation of the bit, as will be hereinafter described.

The means of closing the passage 40 includes a pair of swingably mounted gates 7 and 8. As shown better in FIGS. 2 and 3, the drill head 5 has pairs of spaced ears 10 and 11 on one side, and 12 and 13 on the other side. Gate 7 carries an ear 14 integral therewith, which tits between the spaced ears 10 and 11. Ears 10, 11 and 14 are apertured in alignment to accommodate a hinge pin 15. Gate 8 has a similar integrally formed ear 16, which in turn, fits between the spaced ears 12 and 13. Ears 12, 13 and 16 are apertured to accommodate a hinge pin 17. Thus, both gates 7 and 8 are hingedly connected to the bit head 5.

Referring now to FIGS. l and 2, each side of the drill head has formed integrally therewith, opposite pairs of bosses generally indicated as and 21. In each boss is a drilled socket, such as, 23 and 24 shown in dotted lines in FIGS. l and 2. The other pair of bosses 21 have drilled sockets similarly formed and indicated in FIG. 2 as 26 and 27. Each of the sockets 23, 24, 26 and 27 accommodates a coil spring, such as, springs 30 indicated in FIG. 1. Since all of these springs are identical, only one will be described. Each spring is a tension spring, provided with hooks at its opposite ends, one of these hooks 32, protrudes through a hole 33 in the bottom of each of the sockets and anchors to the upper surface of the boss 20 or 21, as the case may be. The opposite hooked end of a spring protrudes through a hole such as 34 in the gate 7, and its hooked end 35 is held anchored therein by a washer 36. Since each of these springs 30 in each of the sockets is mounted in exactly the same way, it will be apparent that the tension in each of these springs tends to hold the gates 7 and 8 closed on the end of the bit head 5. When the gates 7 and 8 are closed, all of the spring sockets are closed to keep out the cuttings. These springs 30, however, will yield to allow the gates 7 and 8 to open a through passage from the hollow drill string 1, through the hollow shank 3 of the bit 5, and thence through the head of the bit to the bottom of the hole. The manner in which the gates 7 and 8 are opened will appear in the following description.

In the particular embodiment herein described, the gates 7 and 8 form together a semi-spherical cavity, when closed, as shown in FIGS. 3 and 4 particularly. This cavity formed by the gates is substantially the same diameter as of the passage 40 in the head of the bit 5. Each of the gates 7 and 8 form one-half of this semi-spherical like cavity. Bisecting the cavity in the gate 7 is a rib 4-1, which is diametrically opposed to a similar rib 42 on the inner face of the cavity within the gate S. The ribs 41 and 42 are so disposed that when the gates 7 and 8 are closed, the two ribs almost meet to form a continuous rib. The function of these ribs 41 and 42 will appear more fully in the description of the operation of the device. Itis only necessary to point out here that these ribs are in effect cam surfaces by which the gates 7 and 8 are effectively wedged apart to an open position by the insertion of a sample recovery tool, or the like.

As shown in FIG. 2, there is a bit mounting 45 on gate 8 carrying a bit insert 46 on its forward face. Preferably, the bit insert on the forward face is disposed along a diameter through the center of the bit head 5. On the gate 7, there is a similar bit mounting 47, with a bit insert 48 facing in the opposite direction from the insert 46 and disposed in the same manner in respect to a diameter through the bit head 5. Radially, outwardly of the bit mounting 45 and disposed at an angle thereto, is a bit mounting 50 with a bit insert 51 on its forward face. A similar bit mounting 53 is disposed on the gate 7 radially outwardly of the bit mounting 47 and provided with a bit insert 54 on its forward face.

Referring now to FIGS. l and 2, the bit head 5 is provided with bosses containing sockets, inclined sockets 57 and 58, which are inclined in opposite directions from the center line of the bit on opposite sides of the head 5. These sockets 57 and 58 provide seats for bits 63 and 61, respectively, which mount bit inserts 62 and 63, respectively. All of the inserts for the bits are tungsten carbide, or other abrasive resistant material, and the bits are so located as to cut across the full hole diameter, and to protect the hinges from wear and abrasion. From the above description, it will be readily appreciated that the bits 45, 46 and 47 and 48 are grouped centrally of the head 5, and project beyond or ahead of bits 51 and 54 as well as 62 and 63. These centrally located bits are the leading bits or pilot bits on the bit head. Radially outwardly of this central group of pilot bits is a second group including the bits 62 and 63 located to cut at the outer periphery of the hole and follow after the pilot bits. These can be termed outer bits or trailing bits. The bits 51 and 54 are located in trailing relation to the pilot bits and in leading relation to the outer bits, and perform the cutting between these two groups. This pair of bits can be termed a group of inner trailing bits. The outer or trailing bits are replaceable by removing them from sockets 57 and 58 and inserting others. Bits 45, 47 and 51, 54 are replaceable by removing hinge pins 15 and 17 and installing new gates 7 and 8.

With respect to FIGS. l and 2, it will also appear that the bit head 5 carries an auger portion 66 and an auger portion 67, located on opposite sides thereof. The upper trailing ends of these auger portions are adapted to register with the lower leading ends of a pair of spiral conveyor flights 6 carried on the hollow drill string 1. Spiral conveyor flights may be used on each section of the drill string so that the borings from the hole are conveyed upwardly along the outside of the string to the earth surface, all in a manner taught in the aforesaid patent application of Theodore E. Rassicur, above identified.

FIG. 5 is an operational view showing how the cutting head is opened by a sample recovery tool or the like. The cutting head 5 is first raised to the position shown in dotted lines, and, while suspended in this position, a sample recovery tool, or the like, 70 is inserted down the hollow drill string 1, through the shank 3 of the cutting head 5 and forced against the cam surfaces of the ribs 41 and 42. The force exerted by the tool 70 is outwardly directed on the surfaces of the ribs 41 and 42 to swing gates 7 and 8 open against the initial tension of the springs 30 and the tool 70 is allowed to pass to the bottom of the hole. The tool 70 may then be dn'ven into the earth to take a sample, and the tool and sarnple contained therein removed through the drill string for inspection and testing. On removal the gates 7 and 8 are closed by the springs 30, the drill string lowered until the bits are again on the bottom of the hole, and rotary drilling resumed. The gates will not only be held closed by the springs, but also by the pressure of the bits on the bottom of the hole and the torque load on the bits due to resistance of the bits during drilling.

The operation, above described, is subject to modication. Instead of first raising the drill stem 1 and cutting head 5, the process is reversed and the sample recovery tool 70 is first inserted down the stem 1 until it rests against cam surfaces on ribs 41 and 42. With the tool 70 held stationary, cutting head 5 is then raised to the dotted line position opening the gates 7 and 8. Tool 70 can then slide to the bottom of the hole.

If the tool 70 is a sampling tube, it is driven into the earth after passing through the bit head. If the tool 70 is a coring tool, it is rotated to cut a core after passing through the bit head. In any case, after the operation performed by tool 70 is completed, it is usually removed from the stem together with the sample contained therein. Thereafter drilling can be resumed.

Changes in and modifications of the construction described, may be made without departing from the spirit of my invention or sacrificing its advantages.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In a bit for earth boring equipment used in core recovery, said bit having an internal passage forming a continuation of the passage through a hollow drill string with an external auger ight, the improvement comprising,

(a) a hollow shank part with a detachable connection to the lower end of said drill string, and a hollow head part formed on said shank and having an open lower end,

(b) a pair of gates together forming a complete closure for the open lower end of said hollow head part,

(c) a hinge mounting for each of said gates including connecting ears projecting radially outwardly of said gates and ears on the exterior of said hollow head part and detachable means pivotally connecting an ear projecting on each said gate to separate of said ears on the exterior of said hollow head part,

(d) spring means connecting said gates and head part for maintaining said gates closed mounted in sockets in bosses on the exterior of said hollow head part which sockets are closed by said gates when said gates are closed,

(e) a plurality of bits on said gates and axially and radially disposed thereon to drill a hole for passing said hollow head part carrying said gates and said hinge mounting for said gates, only, and,

(f) a plurality of bits carried by said hollow head part projecting outwardly of said bits on said gates and disposed to clear the hole for passing said auger flight,

said bits on said gates being arranged to permit full opening of said gates to pass a coring tool when said bit is in the hole formed by said plurality of bits carried by said hollow head part.

2. In a bit for earth boring equipment used in core recovery, said bit having an internal passage forming a continuation of the passage through a hollow drill string with an external auger flight, the improvement comprising,

(a) a hollow shank part with a detachable connection to the lower end of said drill string, and a hollow head part formed on said shank and having an open lower end,

(b) a pair of gates together forming a complete closure for the open lower end of said hollow head part,

(c) a hinge mounting for each of said gates including connecting ears projecting radially outwardly of said gates and ears on the exterior of said hollow head part and detachable means pivotally connecting an ear projecting on each said gate to separate of said ears on the exterior of said hollow head part,

(d) spring means connecting said gates and head part for maintaining said gates closed and arranged thereon in open ended sockets in said head part which open ends are positioned to be enclosed when said gates are closed,

(e) a plurality of bits disposed in leading and trailing relation on said gates and disposed axially and radially thereon to drill a hole for passing said hollow head part carrying said gates and said hinge mounting for said gates only, and

(f) a plurality of bits carried by said hollow head part projecting outwardly of said bits on said gates and disposed in trailing relation to the bits on said gates to clear the hole for passing said auger flight,

said bits on said gates being arranged to permit full opening of said gates to pass a coring tool when said bit is in the hole formed by said plurality of bits carried by said hollow head part.

3. In a bit for earth boring equipment used in core recovery, said bit having an internal passage forming a continuation of the passage through a hollow drill string with an external auger flight, the improvement comprisms,

(a) a hollow shank part with a detachable connection to the lower end of said drill string and a hollow head part formed on said shank and having an open lower end,

(b) a pair of gates together forming a complete closure for the open lower end of said hollow head part,

(c) a detachable hinge pin mounting for each of said gates including connecting ears projecting radially outwardly of said gates and ears on the exterior of said hollow head part and detachable pin means pivotally connecting an ear projecting on each gate to separate of said ears on the exterior of said hollow head part,

(d) spring means connecting said gates and head part for maintaining said gates closed and arranged thereon in open ended sockets in said head part which open ends are positioned to be enclosed when said gates are closed,

(e) a plurality of bits on said gates disposed axially and radially thereon to drill a hole for passing said hollow head part carrying said gates and said hinge mounting for said gates only and replaceable by disconnection of said detachable hinge pin mounting and substitution of replacement gates, and,

(f) a plurality of bits carried by said hollow head projecting outwardly of said bits on said gates and disposed in trailing relation to the bits on said gates to clear the hole for passing said auger flight,

said bits on said gates being arranged to permit full opening of said gates to pass a coring tool when said bit is in the hole formed by said plurality of bits carried by said hollow head part.

4. In a bit for earth boring equipment used in core recovery, said bit having an internal passage forming a continuation of the passage through a hollow drill string with an external auger ight, the improvement comprislng,

(a) a hollow shank part with a detachable connection to the lower end of said drill string and a hollow head part formed on said shank and having an open lower end,

(b) a pair of gates together forming a complete closure for the open lower end of said hollow head part,

(c) a detachable hinge pin mounting for each of said gates including connecting ears projecting radially outwardly of said gates and ears on the exterior of said hollow head part and detachable pin means pivotally connecting an ear projecting on each gate to separate of said ears on the exterior of said hollow head part,

(d) spring means connecting said gates and head part for maintaining said gates closed mounted in open ended sockets in bosses on the exterior of said hollow head which open ends are closed by said gates when said gates are closed,

(e) a plurality of bits on said gates disposed axially and radially in leading and trailing relation to drill a hole for passing said hollow head part carrying said gates and said detachable hinge pin mounting for said gates only and replaceable by disconnection of said detachable hinge pin mounting and substitution of replacement gates, and,

(f) a plurality of bits carried by said head part projecting outwardly of said bits on said gates and disposed in trailing relation to the bits on said gates to clear the hole for passing said auger flight,

said bits on said gates being arranged to permit full opening of said gates to pass a coring tool when said bit is in the hole formed by said plurality of bits carried by said hollow head part.

References Cited in the tile of this patent UNITED STATES PATENTS 1,741,497 Boltz Dec. 31, 1929 2,170,716 Higgins Aug. 22, 1939 2,330,157 Stokes Sept. 2l, 1943 2,391,869 Bandy lan. l, 1946 2,544,993 Jackson Mar. 13, 1951 2,830,793 Keese Apr. 15, 1958 

1. IN A BIT FOR EARTH BORING EQUIPMENT USED IN CORE RECOVERY, SAID BIT HAVING AN INTERNAL PASSAGE FORMING A CONTINUATION OF THE PASSAGE THROUGH A HOLLOW DRILL STRING WITH AN EXTERNAL AUGER FLIGHT, THE IMPROVEMENT COMPRISING, (A) A HOLLOW SHANK PART WITH A DETACHABLE CONNECTION TO THE LOWER END OF SAID DRILL STRING, AND A HOLLOW HEAD PART FORMED ON SAID SHANK AND HAVING AN OPEN LOWER END, (B) A PAIR OF GATES TOGETHER FORMING A COMPLETE CLOSURE FOR THE OPEN LOWER END OF SAID HOLLOW HEAD PART, (C) A HINGE MOUNTING FOR EACH OF SAID GATES INCLUDING CONNECTING EARS PROJECTING RADIALLY OUTWARDLY OF SAID GATES AND EARS ON THE EXTERIOR OF SAID HOLLOW HEAD PART AND DETACHABLE MEANS PIVOTALLY CONNECTING AN EAR PROJECTING ON EACH SAID GATE TO SEPARATE OF SAID EARS ON THE EXTERIOR OF SAID HOLLOW HEAD PART, (D) SPRING MEANS CONNECTING SAID GATES AND HEAD PART FOR MAINTAINING SAID GATES CLOSED MOUNTED IN SOCKETS IN BOSSES ON THE EXTERIOR OF SAID HOLLOW HEAD PART WHICH SOCKETS ARE CLOSED BY SAID GATES WHEN SAID GATES ARE CLOSED, (E) A PLURALITY OF BITS ON SAID GATES AND AXIALLY AND RADIALLY DISPOSED THEREON TO DRILL A HOLE FOR PASSING SAID HOLLOW HEAD PART CARRYING SAID GATES AND SAID HINGE MOUNTING FOR SAID GATES, ONLY, AND (F) A PLURALITY OF BITS CARRIED BY SAID HOLLOW HEAD PART PROJECTING OUTWARDLY OF SAID BITS ON SAID GATES AND DISPOSED TO CLEAR THE HOLE FOR PASSING SAID AUGER FLIGHT, SAID BITS ON SAID GATES BEING ARRANGED TO PERMIT FULL OPENING OF SAID GATES TO PASS A CORING TOOL WHEN SAID BIT IS IN THE HOLE FORMED BY SAID PLURALITY OF BITS CARRIED BY SAID HOLLOW HEAD PART. 